Automatic disconnect socket assembly



March 11, 1969 M. s. FIELD ET Al- 3,432,629

AUTOMATIC DISCONNEGT SOCKET ASSEMBLY Filed March 5, 1967 Sheet of2 I/V VEN TORS MILTON SCOTT FIELD EDWARD BERNARD B/LSON A ATTORNEYS.

March-11, 1969 M. s. FIELD ET AL AUTOMATIC DISGONNECT SOCKET ASSEMBLY Filed March 5, 1967 INVENTORS M/LTON saorr FIELD EDWARD BERNARD BIL SON- ATTORNEYS United States Patent F 3,432,629 AUTOMATIC DISCONNE'CT SOCKET ASSEMBLY Milton Scott Field, Deerfield, and Edward B. Bilson, Chicago, Ill., assignors, by mesne assignments, to Alm Corp., Chicago, Ill., a corporation of Illinois Filed Mar. 3, 1967, Ser. No. 620,537 US. Cl. 20051.07

3 Claims Int. Cl. H011- 19/54 ABSTRACT OF THE DISCLOSURE Background of the invention This invention relates generally to a lighting equipment socket installation and in particular, to a socket installation preferably with a reflector assembly which is separable electrically and mechanically from a housing, leaving the exposed contacts of the housing electrically dead after separation.

In US. Patent No. 2,917,620 there is disclosed an electric fixture connection of the disconnecting type in which a combination socket and lamp shade is safely removable from its supporting housing while current is passing through the assembly. The structure enables a connection properly to be made Without the need for special polarized orientation of the parts. Fixture connections using this type of assembly are advantageous due to foolproof coupling, and because upon separation of the two main parts, there is an instantaneous break connection between electrical parts so that they can be disconnected while energized without subjecting the fixture to pitting of the contacts. However, upon disassembly of such fixture connection, the exposed electrical contacts of the base housing from which the lamp shade and its socket have been removed remain exposed and electrically alive, thus creating a hazardous condition which subjects workers who come in contact with the base to electric shock and attendant dangers.

Summary of the invention This invention is characterized by a novel supporting hood construction for use with a removable lamp socket or combined socket and reflector which, upon detachment, leaves the exposed contacts of the hood electrically dead, thus eliminating" any likely shock hazard which is present in the case of other hood constructions which have had sockets removed therefrom.

Accordingly, an important object of this invention is to provide adisconnect socket having all of the advantages of the aforementioned patent and additionally, one which, after separation of the main parts, leaves the exposed contacts of the housing electrically dead.

Another important object of the invention is to provide a disconnecting socket installation of the type referred 3,432,629 Patented Mar. 11, 1969 nected by a simple twisting operation which insures predetermined polarity of the lamp socket and load connecting base.

A still further object of the invention is to provide a fixture assembly having a standard lamp socket connector wherein the parts are held together by spring pressure to effect an instantaneous make and break connection between electrical parts so that they may be installed with current on and still avoid pitting of the contacts.

The foregoing and other objects of the invention will become apparent from the ensuing disclosure in which a preferred embodiment has been described in detail in the specification and illustrated in the accompanying drawings. It is contemplated that minor variations in the structure and arrangement of parts thereof may occur to the skilled artisan without departing from the scope or sacrificing any of the advantages of the invention.

Brief description of the drawings FIG. 1 is an elevational view of a disconnect socket assembly constructed in accordance with the invention.

FIG. 2 is a fragmentary partially sectional exploded view of the parts of the socket assembly of FIG. 1 in disconnected condition.

FIG. 3 is a partially sectional view of the parts of the socket assembly of FIG. 1, in connected condition.

FIG. 4 is a bottom end-on plan view of the supporting hood of the invention, looking up from the plane 44 of FIG. 2.

FIG. 5 is a perspective view of a lamp-holding socket constructed in accordance with US. Patent 2,917,620 and adapted for utilization in the invention.

FIG. 6 is a sectional view taken along the line 6-6 of FIG. 4 and in the direction indicated, showing the elements of the supporting hood when the socket assembly is in connected condition.

FIG. 7 is a sectional view similar to that shown in FIG. 6, but showing the elements of the supporting hood when the socket assembly is in disconnected condition.

FIG. 8 is a longitudinal sectional view taken on the line 88 of FIG. 4 in the direction indicated.

FIG. 9 is a top plan view of the inside of the supporting hood unit, with portions of the inner base socket broken away.

Description of the preferred embodiment In FIG. 1 there is shown a typical lighting fixture assembly 10 with which the invention is concerned. Assembly 10 is formed of three principal elements, these being a base or hood 12, a reciprocating contact-establishing or base socket 14 captive in base 12, and a removable lamp-holding socket 1'6 engaged with the reciprocating socket 14. Attached to lamp socket 16 is a reflector element 18. Base 12 is suitable for mounting upon a surface in a conventional manner, and may be pendant, outlet-box or feed-through mounted. The said base provides connection to a source of power. through lead wires 20. On the interior of base 12 is a pair of resilient contacts 22 and 24. Contacts 22 and 24 are adapted to be connected to a source of power by terminal screws 26 mounted on partition member or insulating plate 28. Lugs 88 are mounted on insulating plate 28- by rivets 90. A portion of said lugs extend beyond said rivets into the path of screws 26 A bent-up portion of the lugs surrounds the head of screws 26 to prevent the lead wire 20 from creeping out from beneath the screw-head when the terminal screws are being tightened.

The captive socket 14 has a pair of electrical conductors or pins 30 and 32 presented to the interior of base 12. and aligned with resilient contacts 22 and 24, so that if the socket 14 is pressed against the contacts 22 and 24, the pins 30 and 32 engage the respective contacts. The socket 14 is formed of insulating material and has a female receptacle 34 presented to the end of the base 12 opposite that carrying conductors and 32. Each pin 30 and 32 has a contact 36 and 38 on the interior of receptacle 34. Contacts 36 and 38 are secured to pins 30 and 32 by screws 40 and 42 extending through the end portion 44 of base or captive socket 14.

The captive socket 14 is urged to move out of the base 12 by means of a helical spring 46 that indexes the captive socket 14 properly and provides resistance to twisting. Screws 48, 50 and 52 positioned through the outer wall of base 12 serve as stop means to limit such outward movement so that twisting of the captive socket cannot misalign the pins 30 and 32 relative to their respective interior contacts 22 and 24. Partition member 28 has a hole 54 for receiving a bent extremity 56 of helical spring 46. The other end of spring 56 has a bent extremity 58 engaging in a hole 60 of captive socket 14 so that upon being inserted within base 12, the captive socket 14 is given a slight twist partially to compress spring 46 and likewise to apply torque thereto. Screws 48, 50 and 52 hold captive socket 14 against rotary and axial outward movement relative to the hood 12 due to spring 46. Screws 48, 50 and 52 are also disposed in the path of openings 62 to rest on surfaces 92 in the outer wall of socket 14 extending from the adjacent edge thereof. Said screws are spaced] at equal circumferential distances about the periphery of base 12. Thus, after socket 14 is inserted against the combined compression and torque tension of spring 46 and the screws extend through the wall of hood 12 engaging in the openings 62, the captive socket will be limited in its movement outwardly of the hood by engagement of the screws but may be pressed and twisted inwardly a limited amount until pins 30 and 32 make connection with contacts 22 and 24. Captive socket 14 may still be rotated a limited amount against the torque of the spring 46.

Recesses 64 are provided in the edge of the captive socket 14 intermediate the openings 62, each one of said recesses being diametrically opposite one of the three openings '62.

Lamp-holding socket 16 is constructed in accordance with the disclosure of US. Patent 2,917,620. Socket 16 is provided on its interior with a threaded conductor shell for receiving an electric lamp. Located at the extremity of the socket 16 is a reduced neck 66 of hexagonal form. Annular recesses 68 are positioned at three equi-distant locations about neck 66, for seating a Z-shaped contact 70 having one extremity seated in recess 68 and the other extremity at the outer end of neck 66. Secured upon the end of neck 66 is a center triple contact 72 having three arms to extend against the end of the neck 66 and between contacts 70. The arrangement of three spaced contacts 70 and three arms of the center triple contact 72 insures that one arm of the triple contact and one of the Z-shaped contacts 70 will be located at opposite sides of the neck 66 for engagement with opposite contacts 36 and 38 of the captive socket 14 no matter which one of the arms and contacts is considered. Thus, the polarity of the lamp socket terminals is maintained irrespective of the orientation of parts when the socket is assembled.

The threaded conductor shell is affixed to socket 16 by a plurality of screws which extend to make contact with each of the Z-shaped contacts 70. The center of the socket 16 has another contact for engaging the center contact at the end of an incandescent lamp which is in serted in the socket in a well known manner, this contact being held to socket 16 by a fastening screw 74, the end of which extends through the central portion of the bottom of socket 16 and engages the triple contact 72 at the outer end 66 of socket 16. The lamp receiving shell and contact together with electrical connections to contacts 70 and 72, respectively, are shown schematically in FIG. 2 at 71.

Supporting plate 76 is mounted upon socket 16 around its outer end 66 and is held in place by screws 78 which are insulated from contact with the threaded conductor shell. A non-conducting washer 80 is interposed between plate 76 and socket 16 further to insulate plate 76 from electrical contact with the conductor shell. Three outwardly directed radial ears 82 are formed integral with plate 76 at equidistant locations about the outside periphery of said plate. Ears 82 extend beyond the outer surface of socket 16 and are adapted to be received through correspondingly spaced recesses 84 opening from the inner edge of the inner periphery of the base 12.

To assemble the lamp holding socket 16 upon base 12, socket 16 is positioned upon base 12 so that ears 82 rest in alignment with recesses 84 in base 12. Adjacent recesses 84 are projections 94 on socket 14 which prevent ears 82 from being inserted into recesses 84 when socket 14 is in its extended position. To effect rotation of socket 16, the lamp socket is depressed against projections 94 on captive socket 14 forcing inward movement of the captive socket against the force of spring 46. Depression of lamp socket 16 enables ears 82 to clear lip extensions 86 in base 12 (FIG. 7) which normally block movement of said ears beyond recesses 84. Socket 16 is then twisted in a right hand direction to snap ears 82 into recesses 64 enabling spring 46 to return captive socket 14 a short distance locking the ears in place between the floor of recesses 64 and lip extensions 86. As seen in FIG. 3, when socket 16 is in locked position with base 12, captive socket 14 remains slightly depressed and thus engaging the pins 30, 32 with base contacts 22, 24. The central projection 66 of lamp holding socket 16 then electrically engages the interior contacts of captive socket 14, causing current to flow through the threaded conductor shell to a lamp positioned therein. Ears 82 rest upon the floor of recesses 64 of captive socket 14 and are prevented from being dislodged therefrom by the attendant force of lip extensions 86 hearing down upon ears 82. In this position ears 82 firmly retain socket 16 in assembled position until disconnection is desired.

To remove the lamp-holding socket 16 from its engagement with base 12, socket 16 is twisted to the left and depressed a small amount, forcing screws 48, 50 and 52 to ride up on surface 96 of socket 14. This step aligns cars 82 with recesses 84. The twisting action releases the torque of spring 46. Socket 16 is then removed through recesses 84 to permit captive socket 14 to be pushed outward by the spring 46 a sutficient amount (FIG. 2) to move the pins 30, 32 away from the plane of contact with interior base contacts 22, 24. Upon removal, spring 46 forces socket 14 to return to its original disconnect position. At this time, the contact surfaces of pins 30, 32 will again be directly in line with contacts 22, 24 so that when the socket 16 is to be again installed, the applying action will be repeated as above described.

From the above description, it can be seen that upon mechanical disconnection of the socket 16 from the hood 12, an instantaneous disconnection of the electrical connection to socket 14 is effected. Such instantaneous disconnection prevents the danger of electric shock to a person who may be working on the socket assembly, or even to one who inadvertently reaches his fingers into the socket. Further, the instantaneous disconnection prevents undesired pitting of contacts which results in other systems. When the lamp fixture is in assembled condition, the parts remain firmly in place until removal procedure is followed. The polarity of the lamp socket is maintained irrespective oforientation of the parts when the lampholding socket'i's re-assembled with the base.

It will also be appreciated that the bent extremities 56 and 58 of spring 46 being retained in holes 54, 60 permit the spring to be safely positioned about exposed contacts 22, 24 and pins 30, 32 with no danger of shorting of the electrical contacts resulting. Spring 46 is retained firmly in place by virtue of said bent portions with the result that there is no possibility of said spring moving out of place to cross said contacts.

It is believed that the invention has been described sufiiciently to enable the skilled artisan to understand and practice same. The invention has been defined in the claims in language intended to be broadly and liberally construed commensurate with the achievement represented thereby.

What it is desired to be secured by Letters Patent of the United States is:

1. An automatic disconnect socket assembly, compris- (a) a hollow base having (1) a generally tubular-walled member, and

(2) transverse partition means Within the tubularwalled member having a first pair of electrical contacts therein exposed to one axial face of said partition means and means for connecting a source of electric power to said contacts from the second axial face of said partition means,

(b) a contact-establishing first socket disposed in said hollow base,

(1) said first socket being axially reciprocable within said base between two axially spaced apart positions,

(2) and being provided with a pair of electrical conductors having first parts exposed on one end of said first socket in alignment to be engaged, respectively, with said first pair of contacts when said first socket is located in one axial position closest to said transverse partition means,

(3) said first parts of said pair of electrical conductors being disengaged electrically from said first pair of electric contacts when said first socket is located in its second axial position farthest from said traverse partition means,

(c) means biasing said first socket to move toward said second axial position,

(d) said hollow base and first socket having means limiting said last-mentioned movement to said second axial position both axially and circumferentially relative to said tubular-walled member,

(e) said first socket having its second end facing the axial end of said base opposite the first axial face of said transverse partition means, said conductors having second parts exposed on said second end,

(f) a lamp-holding second socket adapted removably to be coupled into said axial end of said base and having (1) means for mounting and electrically connecting a lamp in one end thereof, and

(2) a second pair of electric contacts in the opposite end thereof connected with said lamp mounting means and disposed at said opposite end in alignment with said second parts and adapted electrically to engage said second parts when said second socket is so coupled, and

(g) said base and second socket having means for securing said second socket in coupled condition but only upon pressing said second socket axially against said first socket and its biasing means to move said first socket to its said one axial position, thereby completing electrical connecting paths between said source connecting means and lamp mounting means, said means for securing said second socket in coupled condition with said base including (1) a plurality of radially extending ears adjacent said second pair of electrical contacts of said second socket,

(2) a plurality of seat portions in said first socket along the peripheral edge of said first socket adjacent said limiting means,

(3) a plurality of projections spaced alternatively of said seat portions adapted to be engaged'by said ears for forcing said first socket into said base against the outward force of said biasing means, and

(4) a plurality of grooves on the inner face of said hollow base adjacent said seat portions, said grooves providing a path for movement of said cars into said seats when said second socket is pressed and rotated axially against said first socket.

2. An automatic disconnect socket assembly as claimed in claim 1 wherein said grooves have axially extending extensions adjacent said projections for firmly retaining said ears in said grooves when said second socket is assembled upon said base.

3. An automatic disconnect lamp-holding apparatus comprising a hollow base, a hollow reciprocating socket captive in said base, and a removable lamp-holding socket engaged with said captive socket, said base having on its interior a pair of resilient electrical contacts for carrying an electrical current to said apparatus, said captive socket having a pair of pins presented to the interior of said base and aligned with said resilient contacts such that when said socket is pressed against said contacts said pins engage the respective contacts, spring means positioned in said base urging said captive socket out of said base and providing resistance to twisting of said socket, stop means on said base limiting said outward movement and said twisting movement of said socket such that twisting of said socket cannot misalign said pins with said interior contacts, said captive socket having a female receptacle presented to the end of said base opposite that carrying said contacts, said female receptacle having seat portions provided thereon, said pins each having a respectively connected contact on the interior of said captive socket, the base having a plurality of grooves adjacent said seat portions, the lamp-holding socket having a central projection for engagement in said female receptacle and radially extending ears for cooperation with said grooves, said grooves providing a path for movement of said ears into said seats such that when said ears are inserted into said grooves against the outward force of said captive socket and moved into said seats, said ears are locked in place and said captive socket is depressed forcing said pins to engage said base contacts.

References Cited UNITED STATES PATENTS 896,838 8/1908 Klein 20051.09 2,917,620 12/1959 Arras 240-78 3,202,812 5/1963 Berry et al 240l.2 X

ROBERT K. SHAEFER, Primary Examiner.

D. SMITH, ]R., Assistant Examiner.

US. Cl. X.R. 20051.09; 24078 

